An enumeration representing the relative date options for calculating a value to be used in
date-based Boolean.
To call an enum, you call its parent class, name, and property. For example, 
SpreadsheetApp.RelativeDate.TODAY.
Properties
| Property | Type | Description | 
|---|---|---|
| TODAY | Enum | Dates compared against the current date. | 
| TOMORROW | Enum | Dates compared against the date after the current date. | 
| YESTERDAY | Enum | Dates compared against the date before the current date. | 
| PAST_WEEK | Enum | Dates that fall within the past week period. | 
| PAST_MONTH | Enum | Dates that fall within the past month period. | 
| PAST_YEAR | Enum | Dates that fall within the past year period. |